Entertainment Tonight -- Brittany Murphy's father, Angelo Bertolotti, has filed a lawsuit against the Los Angeles County Coroner's Office after being dissatisfied by the handling of his daughter's death investigation, according to court papers obtained by ET.

In the documents, Bertolotti states that he disagrees with the findings in the autopsy report, writing that the "testing/toxicology was incomplete and the death of Brittany Anne Murphy Monjack was never fully investigated."

The autopsy reportedly attributed Murphy's death to community-acquired pneumonia and iron deficiency anemia.

In the lawsuit, Bertolotti requests that a judge release his daughter's hair samples so that he might investigate further.

Murphy died on Dec. 19, 2009, five months prior to the death of her husband, Simon, who also reportedly passed from pneumonia and anemia.